Sign constituents
Lexical signs are composed of at least three constituents:
- Handshape - Configuration of the hand and fingers
- Location - Hand location relative to the body
- Movement - Hand movement between locations or hand-internal movement
Some analyses also include the following constituents, which are sometimes called minor parameters:
- Palm Orientation - Orientation of the palms
- Nonmanual parameters (NMP) - Parameters that don't involve the hands, including facial expression
- Contact - Regions of the hand that contact each other or other body parts
- Number of hands - Number of hands used in a sign
Each sign language has a different inventory of available values for each parameter. For example, some handshapes used in ASL are not used in Korean Sign Language and vice versa.
Parameter distribution
Across documentation on 87 sign languages surveyed in the Sign Language Analyses (SLAY) database, all of them include handshape as a distinctive parameter, 98.6% include movement, and 94.25% include location. Conversely, the minor parameters palm orientation, number of hands, and NMPs are present in 52% or fewer of these languages' documentations. (Tatman 2015)
What is a sign language phoneme?
What should be considered a phoneme (or segment) in sign languages is cause for debate.
In some analyses, each of these constituents could be considered a phoneme that is articulated simultaneously with the other segments in the sign, while in other analyses the entire sign is a single phoneme and each constituent is a feature analogous to the features in spoken language phonemes (e.g. voiced, obstruent, nasal).